Electrolytic pump operated gas bearing

ABSTRACT

There is disclosed a hydrostatic gas bearing supplied with hydrogen at high pressure from an electrolytic cell operated in a pumping mode. A high purity hydrogen gas at high steady pressure is transmitted through an electrolytic cell using hydrogen diffusion anode and a hydrogen diffusion cathode and an electrolyte therebetween. With a voltage across the electrodes and with the anode and cathode chambers charged with hydrogen and a flow restrictor in the external fluid path between the chambers, hydrogen is transmitted through the anode, electrolyte and cathode to develop superatmospheric pressure in the cathode chamber and subatmospheric pressure in the anode chamber. The hydrostatic gas bearing with its associated load device is suitably operated in a closed container with the high pressure hydrogen applied to its inlet passage and the container being partially evacuated by connection to the low pressure chamber of the electrolytic cell thereby reducing the windage loss in operation of the load device.

OR 3 t 586 43s willow utalcb W 172] Inventors Carlo DelCnm liticn:

Keith R. Jenkin. Warren. both of. Mich. [Zll Appl No 882.174 [22] FiledDee. 1969 [45] Patented June 22. 197] [73] Assignee SpeedringCorporation Warren. Mich. 3 s.)

[54] ELECTROLYTIC PUMP OPERATED GAS H H H 3,586,435

Primary E.raminerMartin P Schwadron Assistant Examiner Frank SuskoAttorney-Barnard, McGlynn and Reising ABSTRACT: There is disclosed ahydrostatic gas bearing supplied with hydrogen at high pressure from anelectrolytic cell operated in a pumping mode. A high purity hydrogen gasat high steady pressure is transmittedlthrough an electrolytic cellusing hydrogen diffusion anode and a hydrogen diffusion cathode and anelectrolyte therebetween. With a voltage BEAUNG across the electrodesand with the anode and cathode cham- 25 Clalms, 9 Brown; Figs.

bers charged with hydrogen and a flow restrlctor in the exterl l Cl350/7 nal fluid path between the chambers, hydrogen is transmitted303/910429 through the anode, electrolyte and cathode to develop su-[Sl] Int. Cl ..G02bl7/00, peratmospheric pressure in the cathode chamberand ub t- F 1 6C l Col b 13/04 mospheric pressure in the anode chamber.The hydrostatic gas [50] Field 0' Search 204/ l 29; b i ith its s iatedload devige is suitably operated in a 350/ 7 closed container with thehigh pressure hydrogen applied to its inlet passage and the containerbeing partially evacuated by [56] Rdmnm and connection to the lowpressure chamber of the electrolytic cell UNITED T T PATENTS therebyreducing the windage loss in operation of the load 3,448,035 6/1969Sert'ass 204/278 device.

y In 5 34 .k 24! s 750 2/8 l I A -..""l "5 (6 i POWER 4 1/0 ELECTROLYTICPUMP OPERATED GAS BEARING This inventiori relates to hydrostatic gasbearings and, more particularly, to process and apparatus for supplyinggas pressure to such bearings.

It has been a common practice heretofore in the operation of hydrostaticgas bearings to utilize a conventional compressor, usually of the pistontype, for supplying air or other gas at high pressure to the journal ofthe gas bearing. While such an arrangement is suitable for someapplications, there are certain gas bearing applications where themechanical compressor poses difficult problems and is highlyobjectionable. Such compressors are extremely noisy and producemechanical vibrations of large amplitude over a wide frequency spectrum.Consequently, unless the equipment is suitably muffled and isolated, itis a source of interference with surrounding equipment. Additionally,such compressors are relatively large and heavy and require substantialpower, operate at a relatively low efficiency and require continualmaintenance. Generally, gas bearings operated with compressors utilizeatmospheric air and hence involve gaseous components of relatively highviscosity. Even when a selected gas is recirculated in aclosed system bya compressor, it is subject to a high degree of contamination by thecompressor, which may impair operation of the bearing or the deviceassociated therewith.

In a particular application a hydrostatic gas bearing is employed in alaser scanner of the type wherein a mirror is rotated at exceedinglyhigh speeds over a wide dynamic range. In such equipment great precisionis required in speed control and because of the optical system a highdegree of stabilization must be provided. Because of the high rotativespeeds, the scanner is desirably operated in a closed chamber which isevacuated to a low gas pressure to minimize the windage loss. Since theoptical transmission path must extend through the closed chamber,windows are provided therein which, in addition to the mirror surfaces,must be kept free of contamination to avoid impairment of thetransmission path. In such an application the conventional compressorleaves much to be desired. The vibration produced by the compressor,unless satisfactorily isolated, will interfere with the properfunctioning of the laser scanner. Furthermore, pulsations in the gaspressure supplied to the bearing by the compressor may produce somedisturbance in the scan rate unless suitably damped. Contaminants suchas hydrocarbons from the compressor and water vapor entrained in the gasmay be deposited upon the optical surfaces of the mirror and windows inthe laser scanner and impair the optical transmission. Furthermore, inthe operational environment for such equipment the noise of thecompressor is highly objectionable.

It has been recognized for some time that hydrogen gas has propertieswhich are most desirable for use in the hydrostatic gas bearing.Hydrogen, for example, has a very low viscosity coefficient and,therefore, the losses in a high-speed bearing are minimized. It has ahigh thermal conductivity and is nonreactive with other materials usedin connection with gas bearings. It is readily available and economicalin commercially pure form. One major drawback, however, of hydrogen gashas thus far militated against its use in gas bearings; that is thepotential hazard of explosion when stored in substantial quantity.Because of this characteristic the so-called cylinder hydrogen has notbeen acceptable for use in aircraft and other environments where thereis a risk of explosion.

In accordance with this invention, process and apparatus are providedfor supplying. gas, particularly hydrogen gas, to a hydrostatic gasbearing in a manner which obviates the aforementioned problems in theprior art. This is accomplished by generating a gas flow by means of anelectrolytic cell, restricting the flow to produce a relatively highpressure and supplying the high pressure gas flow to the inlet passageof the bearing. This process and the apparatus required therefor isespecially well adapted for the production of high purity hydrogen gasat high, steady pressure. This is desirably achieved by using anelectrolytic cell'of the type-including a hydrogen diffusion cathode forevolving and transmitting hydrogen gas at high pressure from anelectrolyte to a high-pressure chamber. Desirably, the anode is of thesame material adapted for hydrogen diffusion and transmits hydrogen froma low-pressure chamber to the electrolyte. With a voltage across theelectrodes, hydrogen gas is supplied at superatmospheric pressure to thebearing and recirculated through the electrolytic cell. The bearing andits load device may be operated in a closed chamber with the highpressure being applied to the journal which communicates with thelow-pressure anode chamber of the cell and is thereby pumped tosubatmospheric pressure. The cathode and anode electrodes are preferablyformed of a solid metal alloy of palladium and silver and theelectrolyte is desirably a highly concentrated aqueous solution ofsodium hydroxide. The electrodes are suitably of tubular configurationand one may be disposed within the other with the electrolytetherebetween. A plurality of the electrolytic cells may beinterconnected electrically with the fluid circuits connected inparallel to supply the required volume of gas flow to the gas bearing.Pressure responsive means connected with at least one of the pressurechambers and with the voltage source may be utilized to vary the cellcurrent to regulate the pressure at a desired value.

A.more complete understanding of this invention may be obtained from thedetailed description which follows taken with the accompanying drawingsin which FIG. 1 is a diagrammatic representation of the inventive systemincluding a hydrostatic gas bearing and electrochemical pump;

FIG. 2 shows a single electrolytic cell adapted. for use in the presentinvention;

FIG. 3 is a fragmentary view of a bank of electrolytic cells of the typeshown in FIG. 2; and

FIG. 4 is a diagram showing the interconnection of plural cell banks.

Referring now to the drawings, there is shown an illustrative embodimentof the invention in a system utilizing a hydrostatic gas bearing in alaser scanner. in general, the system comprises a laser scanner toincluding a hydrostatic gas bearing which is supplied with gas pressurefrom an electrochemical pump 12 which is provided with a power supplyand control system 14.

Consider first the laser scanner 10 which may be regarded as the loaddevice or utilization device of the system. It comprises a sealedenvelope or container 16 within which is disposed a fixed bearing shaft18 having its ends fixedly mounted in the opposed end walls of thecontainer 16. The shaft 18 is provided with a thrust plate 20 adjacentone end and a similar thrust plate 22 adjacent the other end. A spinnerassembly or rotor 24 having a smooth axial bore is fitted over the shaft18 between thrust plates 20 and 22 with exceedingly small clearance andvery close tolerances. In order to rotatably drive the rotor 24, ahysteresis motor 26 is mounted inside the container 16 with its statorsecured thereto and with a hysteresis ring 30 secured to the rotor 24.The rotor 24 is provided with a multifaceted mirror 32 which includes aplurality of reflective surfaces 34 each of which is disposed on the rimthereof and extends in a tangential plane. The chamber 16 is providedwith optical windows 36 and 38 disposed radially outwardly from thereflective surfaces 34.

The hydrostatic gas bearing of the laser scanner 10 comprises a journal40 which is supplied with gas at high pressure through an inlet passage42 in the shaft 18. The passage 42 includes a set of radially extendingorifices 44 and another set of radially extending orifices 46 whichsupply a gas under pressure to the radial portion of the journal 40. Theinlet passage 42 also includes a set of axially extending orifices 48 inthe thrust plate 20 and a set of axially extending orifices $0 in thethrust plate 22 to supply gas under pressure to the axial portion of thejournal 40. The orifices which admit gas to the journal 40 and thejournal itself constitute flow restrictors in the path of the gas flowin the inlet passage 42. The journal 40 is provided with an outletpassage 54 formed by the clearance between the rotor 24 and the thrustplate 20. Another outlet passage 56 is provided by the clearance betweenthe rotor 24 and the thrustplate 22. Accordingly, a substantial pressuredifferential occurs across the flow restrictors between inlet passage 42and outlet passages 48 and 50.

In operation of the laser scanner with the hydrostatic gas bearing justdescribed, gas is supplied at high pressure to the inlet passage 42 froma supply conduit 58 and is discharged at low pressure through the outletpassages 54 and 56 to the interior of container 16 from whence it isexhausted by a return conduit 60. With the hysteresis motor 26 energizedand the rotor 24 rotating at high speed, the operation of the opticalsystem may be initiated. This system includes a laser (not shown) fromwhich a laser beam is transmitted through the window 36 and is reflectedsuccessively by the reflective surfaces 34 to produce a repetitive scanpattern. A typical laser scanner bearing requires hydrogen flow of about0.2 cubic feet per minute with an inlet pressure of about 150 p.,s.i.absolute. An outlet pressure below atmospheric such as about 5 or 6 psi.absolute is desired.

In order to supply the gas under pressure to the hydrostatic gasbearing, there is provided, in accordance with the present invention, anelectrochemical pump 12 which will be described with reference to FIGS.2, 3 and 4. The elec trochemical pump 12 comprises at least oneelectrolytic cell,

such as that shown in FIG. 2; in the illustrated embodiment it comprisesa multiplicity of such cells.

It is well known that hydrogen diffuses into some metals and when such ametal, e.g. palladium, is made the cathode in an electrolytic cell,hydrogen will pass through the metal at'room temperature in appreciablequantities. The diffusion rate of hydrogen increases rapidly withtemperature. When the palladium cathode is formed as the wall of a gaschamber, which may be vented through a suitable flow restrictor,hydrogen pressure of several hundred pounds per square inch may be builtup in the chamber. lt is known that other metals such as iron andaluminum also transmit hydrogen to a substantial extent and certainother metals show a lesser degree of hydrogen transmission. Thephenomena has been demonstrated using either an acid electrolyte, suchas sulfuric acid, or a base electrolyte such as sodium hydroxide. Anapplication of such an electrolytic cell for the generation of hydrogenis disclosed in US. Pat.'No. 2,749,293.

Such an electrolytic cell has heretofore been proposed for use ingenerating pure hydrogen as a carrier gas for gas chromotography by theprocess of water electrolysis. Such a cell and the process for operationthereof utilizing a cathode formed of a metal alloy of palladium andsilver is disclosed in US. Pat. No. 3,448,035.

A distinct modification of such water electrolysis cells for theproduction of hydrogen at elevated pressures has also been proposedwhereby the electrolytic cell may be operated in a hydrogen pumpingmode. In this arrangement both the anode and cathode are fonned of ametal adapted for hydrogen diffusion and a low-pressure hydrogen supplychamber utilizes the anode as a part of the chamber wall and ahigh-pressure hydrogen chamber utilizes the cathode as part of thechamber wall. A liquid electrolyteis disposed between the electrodes andthe chambers are charged with hydrogen gas. With a voltage appliedbetween the electrodes, the current is proportional to the hydrogentransferred from one chamber to the other. At the anode hydrogen gasdissociates at the gas phase surface and enters the metal and diffusesto the electrolyte side where it is anodically consumed. At the cathodesurface the action is reversed with the hydrogen formed at theelectrolyte interface entering the metal and diffusing to the gas phaseside. The reactions involved indicate that only hydrogen ha beentransferred from the anode chamber to the cathode chamber. If thehydrogen gas pressure in the cathode chamber is equal to that in theanode chamber the theoretical voltage and the power required would bezero. However, there are small power requirements because of overvoltageat each electrode and ohmic losses due to the current between theelectrodes. The excess voltage can be ofivery low value such as lessthan one-tenth volt and depends upon the electrode current density,transfer for a given electrode area.

In this arrangement if the flow of hydrogen out of the cathode chamberis restricted, superatmospheric pressures of hydrogen such as severalhundred pounds per square inch may be developed. Similarly, if the flowof hydrogen into the anode chamber is restricted, the hydrogen pressuretherein will be reduced to subatmospheric values such as 5 or 6 poundsper square inch.

in this type of cell the presently preferred construction utilizes acathode and an anode of thin tubular membranes of an alloy of about 25per cent silver and about 75 per cent palladium. The electrolyte is aconcentrated aqueous solution of approximately weight percent sodiumhydroxide. The voltage between electrodes is maintained at about 0.09volts and the cell is maintained at an operating temperature ofapproximately 200C. An important requirement in the operation of thecell is that substantially all of the hydrogen at the cathode enter themetal with no hydrogen gas bubbles formed on the electrolyte side. Theideal condition is referred to an l00 percent hydrogen transmission. Inpractical cells this condition has been approached for extendedoperating periods and it has been found that hydrogen transmissionslightly less than the ideal condition produces satisfactoryperformance.

Referring now to FIG. 2, there is shown in diagrammatic fashion anelectrolytic cell 60 of the type referred to above for operation in ahydrogen pumping mode. The cell comprises a container 62, suitably ofstainless steel, within which is disposed a tubular anode 64 ofnonporous or solid metal, preferably an alloy of 25 percent silver and75 percent palladium. The outer end of the anode electrode 64 ishermetically sealed to the wall of the container 62 by a seal 66,suitably of Teflon, thus forming an anode gas chamber 68 which isprovided with a return conduit 70. The cell also includes a cathode 72of tubular form with its inner end closed and disposed within the anode64. The anode is preferably constructed of the same material as thecathode and both electrodes are formed as tubular membranes having awall thickness of approximately five or six thousandths of an inch. Thecathode defines a high-pressure gas chamber 74 and the outer end thereofis adapted for connection to a high-pressure supply conduit. A liquidelectrolyte 76 is contained in the space between the cathode and anodeand preferably comprises an aqueous solution of sodium hydroxide at highconcentration' of approximately 80 weight percent. The electrolyte issealed in the space between the electrodes by an annular seal 76,suitably of Teflon, disposed between the electrodes. The electrolyticcell is maintained at a desired operating temperature preferablyapproximately 200 C. by an electrical resistance heater 78 having itswindings disposed within the container 62 and its electrical terminalsextending through the wall thereof. The operating voltage for theelectrolytic cell is provided by a voltage source 80 having its negativeterminal connected to the cathode and its positive terminal connected tothe anode, the applied volta e being preferably in the vicinity ofone-tenth of a volt.

In the operation of the electrolytic cell in a hydrogen-pumping mode,the anode gas chamber 68 is charged with hydrogen gas from a suitablesource of supply and the cathode gas chamber 74 is connected through aconduit to the desired load device and flow restrictor and the cell isoperated until a 'desired charge of hydrogen has been assumed from theexternal source. Then the external source may be disconnected and thereturn conduit 70 may be reconnected to the exhaust conduit from theload device. Continued operation of the cell thus provides recirculationof the hydrogen gas from the high-pressure cathode gas chamber 74through the load device and back through the exhaust conduit to thelow-pressure anode chamber 63. In this mode of operationsuperatmospheric hydrogen pressure is developed in the cathode chamber74 and subatmospheric pressure is developed in the anode chamber 68.

i.e., the rate of hydrogen It will now be appreciated that a singleelectrolytic cell 60' could be designed and adapted as the hydrogen pumpfor the operation of a load device. However, the gas flow requirementsfor a hydrostatic bearing in a laser scanner are of such magnitude inrelation to the current requirements for the electrolytic cell that apreferred system design utilizes a plurality of electrolytic cells 60 toconstitute the electrochemical pump 12. The arrangement andinterconnection of the cells is shown in FIGS. 3 and 4. Referring firstto FIG. 3, a bank 81 of cells comprises a sealed housing 82 which isdivided by a header or wall 84 into a low-pressure anode chamber 86 anda high-pressure cathode chamber 88. A plurality of electrolytic cells60' and 60" of the type described with reference to FIG. -2 are disposedwithin the housing 82 and mounted on the wall 84. It is noted that theelectrolytic cells 60' and 60" within the bank of cells are connected inelectrical series with each other across the voltage source, i.e., theanode of cell 60' connected to the positive terminal of the voltagesource and the cathode is connected to the anode of the cell 60 whilethe cathode of the latter is returned to the negative terminal of thevoltage source. Such an arrangement enables the use of power supplyhaving a supply voltage greater than that required by each individualcell and determined by the number of cells connected in series in eachbank. It is further noted that all of the cells within the bank have thefluid circuits connected in parallel with a common low-pressure anodechamber 86 having a return conduit 90. All of the cells have a commonhigh-pressure cathode chamber 88 connected to a supply conduit 92. Thecells are suitably maintained at the desired operating temperature bythe respective resistance heaters 78' and 78".

As illustrated in FIG. 4, a plurality of cell banks of the type shown inFIG. 3 are connected together to form the electrochemical pump 12. Inthis arrangement the several cell banks have their electrical circuitsconnected in parallel and the gas fiow circuits are connected inparallel. Each cell band 81, 81' and 81" respectively, connected throughthe return conduits 90, 90' and 90" to a main return conduit 60 which isconnected to the container 16 of the laser scanner [0, as shown inFIG. 1. Similarly, the high pressure cathode chambers 88, 88' and 88",respectively, of the cell banks 81, 81' and 81" are connected throughsupply conduits 92, 92' and 92 to the main supply conduit 58 which isconnected to the inlet passage 42 of the journal 40 in the laser scanner10. With the electrical terminals of the cell banks 81, 81' and 81 beingconnected in parallel across the voltage source, a failure, such as anopen circuit in a single cell, will only disable the one particular cellbank.

The electrochemical pump 12, as just described, for supplying hydrogenpressure to the laser scanner is provided with a power source andcontrol system 14, as indicated in FIG. 1. It is desired to operate thepump 12 so as to obtain a substantially constant pressure differentialacross the journal of the gas bearing. The power source 94 is suitablyan aircraft power supply of 24 volt alternating current at a frequencyof 400 Hertz. The output of the power source is supplied through atransfonner 96 to obtain a desired decrease in the alternating currentvoltage. The output of the transfonner is applied across a full-wavebridge rectifier 100 to develop a DC voltage across its outputterminals, on conductors 102 and 104, which are connected with the cellbanks and individual cells, as indicated in FIGS. 3 and 4. The rectifier100 is suitably of the type employing silicon-controlled rectifiers witha switching circuit whereby the conduction angle thereof may becontrolled to regulate the average value of the output current. For thispurpose the control system includes a modulator 106 adapted to controlthe switching angle of the silicon-con trolled rectifier devices in therectifier 100 in response to the pressure differential across thejournal 40 in the laser scanner 10. A pressure switch 108 is connectedat one side by a conduit 110 to the high-pressure supply conduit 58 andis connected at its other side by a conduit 112 to the low-pressure orexhaust conduit 60. When the pressure differential increases to anexcessive value, as sensed by the pressure switch 108, the modulator 106is effective to reduce the conduction angle in the rectifier and therebyreduce the magnitude of'the current through the electrolytic cells.Similarly, as the pressure differential decreases below the desiredvalue the modulator and rectifier are efi'ective to increase the currentthrough the electrolytic cells and thereby increase the pressure. A trap116, such as a molecular sieve, may be connected in the return conduit60 to remove any contaminants in the gas such as hydrocarbons or aminesthat may be introduced by the motor or other such source. Thus, there isless likelihood of deleterious efiects on the hydrogen transmission atthe cathode of the cell. The heater 118 with its associated thermostaticcontrol 1 may be connected to the secondary of the transformer 96 tomaintain the pump 12 at the desired operating temperature.

Although the description of this invention has been given with respectto a particular embodiment thereof, it is not to be construed in alimiting sense. Many variations and modifications within the spirit ofthe invention will now occur to those skilled in the art. For adefinition of the invention reference is made to the appended claims.

The embodiments of the invention in which we claim an exclusive propertyor privilege are defined as follows:

l. The process of operating a hydrostatic gas bearing com prising thesteps of; generating a 'gas flow by means of an electrolytic gas cell,restricting the flow of gas to produce a relatively high-pressure gasfiow, and supplying the high-pressure gas fiow to the inlet passage ofthe bearing.

2. The process of supplying hydrogen gas under pressure to a hydrostaticgas bearing comprising the steps of; generating a fiow of hydrogenthrough a hydrogen diffusion cathode in an electrolytic cell,restricting the flow of hydrogen emitted from said cathode to produce ahigh pressure and supplying the high-pressure hydrogen to the inletpassage of the bearing.

3. The process of supplying hydrogen gas at high steady pressure to ahydrostatic gas bearing comprising the steps of; generating a flow ofhydrogen in an electrolytic cell of the type including a hydrogendiffusion anodic electrode and a hydrogen diffusion cathodic electrodewith a gas chamber on one side of each electrode and a liquidelectrolyte on the other side of each electrode, charging said gaschambers with hydrogen gas, applying a voltage across said electrodesand circulating the hydrogen gas diffused through the cathodic electrodethrough the gas bearing to the anode.

4. The process of supplying pure hydrogen at high steady pressure to ahydrostatic gas bearing of a load device in a sealed container andhaving an inlet passage connected to the journal of the gas bearing andan outlet passage from the journal to said container, said processcomprising the steps of; generating a flow of hydrogen in anelectrolytic cell of the type including a hydrogen diffusion anodicelectrode and a hydrogen diffusion cathodic electrode with a gas chamberon one side of each electrode and a liquid electrolyte on the other sideof each electrode, charging said gas chambers with hydrogen gas,applying a voltage across said electrodes, circulating the hydrogen gasfrom the cathodic electrode through said gas bearing to the anodicelectrode with sufficient flow restriction in the external flow path ofsaid hydrogen to produce superatmospheric pressure in the inlet passageof said bearing and subatmospheric pressure in the outlet passagethereof and in said container.

5. The invention as defined in claim 4 including the step of modulatingthe current'fiow between said electrodes to obtain substantiallyconstant pressure-differential between said inlet and outlet passages ofsaid bearing.

6. in combination with a load device having a hydrostatic gas bearingwith supply and exhaust passages, an electrolytic cell including anodicand cathodic electrodes with an electrolyte therebetween, a voltagesource connected between the electrodes, means for collecting the gasevolved at one of said electrodes, and means for conveying said gas tothe supply passage of said bearing. 7

7. The invention as defined in claim 6 wherein said gas is hydrogenevolved at said cathodic electrode.

I. The invention a defined in claim I wherein said means for collectingis a chamber having a wall portion fonned by the cathodic electrode, thecathodic electrode being adapted to transmit hydrogen by diffusion fromone surface to the other.

9. The invention as defined in claim 8 wherein said cathodic electrodeis a solid metal alloy of palladium and silver.

10. The invention as defined in claim 9 wherein said cathode is tubularwith one end closed and the other end connected to said supply passage.

11. In combination with a load device having a hydrostatic gas bearingwith supply and exhaust passages, an electrolytic cell including anodicand cathodic electrodes with an electrolyte therebetween, a voltagesource connected between the electrodes, each of said electrodes beingin the form of a membrane and of a material adapted to transmit hydrogenby diffusion from one of its surfaces to the other, said cell includinga low-pressure inlet chamber having a wall portion formed by the anodicelectrode, a high-pressure outlet chamber having a wall portion formedby the cathodic electrode, hydrogen gas in said chambers, a conduitconnecting said high-pressure chamber to the supply passage of saidbearing and a conduit connecting said exhaust passage of said bearing tothe lowpressure chamber of said cell.

12. The invention as defined in claim I] wherein both of said electrodesare constructed of a solid metal alloy of palladium and silver.

13. The invention as defined in claim 12 Wherein both of said electrodesare tubular and one is disposed inside the other.

14. The invention as defined in claim 11 including pressure responsivemeans connected with at least one of said chambers and with said voltagecourse and adapted to vary the current flow through the cell inaccordance with said pressure changes.

15. The invention as defined in claim 14 including heating means adaptedto maintain the cell at substantially constant temperature.

16. In combination a load device including a hydrostatic gas bearingwithin a sealed container, the bearing having an inlet passage connectedwith the journal of the bearing and an outlet pasage from the journal tothe container, an electrolytic cell including anodic and cathodicelectrodes with an electrolyte therebetween, a voltage source connectedbetween the electrodes, each of said electrodes being in the town of amembrane and of a material adapted to transmit hydrogen by diffusionfrom one of its surfaces to the other, said cell including alow-pressure inlet chamber having a wall portion formed by the anodicelectrode, a high-pressure outlet chamber having a wall portion formedby the cathodic electrode, hydrogen gas in said chamber, a conduitconnecting said high-pressure chamber to the inlet passage and a conduitconnecting the container to the low-pressure chamber of said cell.

17. The invention as defined inclaim 16 wherein said electrodes areconstructed of a solid metal alloy of palladium and silver.

18. The invention as defined in claim 17 wherein said cathodic electrodeis tubular with one end closed and the other end connected to said inletpassage.

19, The invention as defined in claim 16 wherein both of said electrodesare tubular and one is disposed inside the other.

20. The invention as defined in claim 16 including pressure responsivemeans connected with at least one of said chambers and with said voltagesource and adapted to vary the current flow through the cell inaccordance with pressure changes.

21. The invention as defined in claim 16 wherein both of said electrodesare composed of a palladium and silver alloy of about 25 percent andabout 75 percent palladium and wherein said electrolyte is an aqueoussolution of sodium hydroxide at a concentration of approximately weightpercent of sodium hydroxide and wherein said cell is operated at atemperature of about 200C.

22. A load device having a hydrostatic gas bearing with supply andexhaust pauages, a plurality of electrolytic cells each having anodicand cathodic electrodes with an electrolyte therebetween, each of theelectrodes being in the form of a membrane and of a material adapted totransmit hydrogen by diffusion from one of its surfaces to the other, alow-pressure inlet chamber, each of said cells having one side of itsanodic electrode communicating with the inlet chamber, a high-pressureoutlet chamber, each of said cellshaving one side of its cathodicelectrode communicating with the outlet chamber, the high-pressureoutlet chamber being connected with the supply passage of the bearingand the low-pressure inlet chamber being connected with an exhaustpassage of the bearing, and voltage supply means connected with each ofsaid cells whereby hydrogen gas is circulated through the bearing.

23. The invention as defined in claim 22 wherein the voltage supplymeans includes a voltage source with said cells being connected inseries with each other across the voltage source.

24. The invention as defined in claim 22 wherein said plurality of cellsincludes first and second groups of cells, said voltage supply meansincludes a voltage source with the cells of each group being connectedin series with each other across the voltage source and the first andsecond groups of cells being connected in parallel across the voltagesource.

25. The invention as defined in claim 22 wherein said load devicecomprises a laser scanner in a sealed container and the low-pressureinlet chamber is connected with the exhaust passage of the bearingthrough said container whereby said container is evacuated to a lowpressure thereby reducing the windage loss arising from high-speedrotation of said scanner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 586435 Dated June 22 1971 I Carlo DelCarlo and Keith R. Jenkin It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 4, line 29 after "above" insert -adapted-. Column 5, line 36bamT' should be --bank: line 37 after "81" insert --has its low pressureanode chamber 86, 86' and 86",-. Column 8, line 17 after "25%" insert-silver.

Signed and sealed this 25th day of January 1972.

(SEAL) Attest:

EDWARD M.FLETCHER ,JR ROBERT Q CHALK Attasting Officer Commissioner ofPatents FORM FWD-1050110459) uscoMM-Dc 6O376P69 U 5 GOVERNMENT PRINTNGOFFICE 7 i969 0*!66-334

2. The process of supplying hydrogen gas under pressure to a hydrostaticgas bearing comprising the steps of; generating a flow of hydrogenthrough a hydrogen diffusion cathode in an electrolytic cell,restricting the flow of hydrogen emitted from said cathode to produce ahigh pressure and supplying the high-pressure hydrogen to the inletpassage of the bearing.
 3. The process of supplying hydrogen gas at highsteady pressure to a hydrostatic gas bearing comprising the steps of;generating a flow of hydrogen in an electrolytic cell of the typeincluding a hydrogen diffusion anodic electrode and a hydrogen diffusioncathodic electrode with a gas chamber on one side of each electrode anda liquid electrolyte on the other side of each electrode, charging saidgas chambers with hydrogen gas, applying a voltage across saidelectrodes and circulating the hydrogen gas diffused through thecathodic electrode through the gas bearing to the anode.
 4. The processof supplying pure hydrogen at high steady pressure to a hydrostatic gasbearing of a load device in a sealed container and having an inletpassage connected to the journal of the gas bearing and an outletpassage from the journal to said container, said process comprising thesteps of; generating a flow of hydrogen in an electrolytic cell of thetype including a hydrogen diffusion anodic electrode and a hydrogendiffusion cathodic electrode with a gas chamber on one side of eachelectrode and a liquid electrolyte on the other side of each electrode,charging said gas chambers with hydrogen gas, applying a voltage acrosssaid electrodes, circulating the hydrogen gas from the cathodicelectrode through said gas bearing to the anodic electrode withsufficient flow restriction in the external flow path of said hydrogento produce superatmospheric pressure in the inlet passage of saidbearing and subatmospheric pressure in the outlet passage thereof and insaid container.
 5. The invention as defined in claim 4 including thestep of modulating the current flow between said electrodes to obtainsubstantially constant pressure differential between said inlet andoutlet passages of said bearing.
 6. In combination with a load devicehaving a hydrostatic gas bearing with supply and exhaust passages, anelectrolytic cell including anodic and cathodic electrodes with anelectrolyte therebetween, a voltage source connected between theelectrodes, means for collecting the gas evolved at one of saidelectrodes, and means for conveying said gas to the supply passage ofsaid bearing.
 7. The invention as defined in claim 6 wherein said gas ishydrogen evolved at said cathodic electrode.
 8. The invention as definedin claim 7 wherein said means for collecting is a chamber having a wallportion formed by the cathodic electrode, the cathodic electrode beingadapted to transmit hydrogen by diffusion from one surface to the other.9. The invention as defined in claim 8 wherein said cathodic electrodeis a solid metal alloy of palladium and silver.
 10. The invention asdefined in claim 9 wherein said cathode is tubular with one end closedand the other end connected to said supply passage.
 11. In combinationwith A load device having a hydrostatic gas bearing with supply andexhaust passages, an electrolytic cell including anodic and cathodicelectrodes with an electrolyte therebetween, a voltage source connectedbetween the electrodes, each of said electrodes being in the form of amembrane and of a material adapted to transmit hydrogen by diffusionfrom one of its surfaces to the other, said cell including alow-pressure inlet chamber having a wall portion formed by the anodicelectrode, a high-pressure outlet chamber having a wall portion formedby the cathodic electrode, hydrogen gas in said chambers, a conduitconnecting said high-pressure chamber to the supply passage of saidbearing and a conduit connecting said exhaust passage of said bearing tothe low-pressure chamber of said cell.
 12. The invention as defined inclaim 11 wherein both of said electrodes are constructed of a solidmetal alloy of palladium and silver.
 13. The invention as defined inclaim 12 Wherein both of said electrodes are tubular and one is disposedinside the other.
 14. The invention as defined in claim 11 includingpressure responsive means connected with at least one of said chambersand with said voltage course and adapted to vary the current flowthrough the cell in accordance with said pressure changes.
 15. Theinvention as defined in claim 14 including heating means adapted tomaintain the cell at substantially constant temperature.
 16. Incombination a load device including a hydrostatic gas bearing within asealed container, the bearing having an inlet passage connected with thejournal of the bearing and an outlet passage from the journal to thecontainer, an electrolytic cell including anodic and cathodic electrodeswith an electrolyte therebetween, a voltage source connected between theelectrodes, each of said electrodes being in the form of a membrane andof a material adapted to transmit hydrogen by diffusion from one of itssurfaces to the other, said cell including a low-pressure inlet chamberhaving a wall portion formed by the anodic electrode, a high-pressureoutlet chamber having a wall portion formed by the cathodic electrode,hydrogen gas in said chamber, a conduit connecting said high-pressurechamber to the inlet passage and a conduit connecting the container tothe low-pressure chamber of said cell.
 17. The invention as defined inclaim 16 wherein said electrodes are constructed of a solid metal alloyof palladium and silver.
 18. The invention as defined in claim 17wherein said cathodic electrode is tubular with one end closed and theother end connected to said inlet passage. 19, The invention as definedin claim 16 wherein both of said electrodes are tubular and one isdisposed inside the other.
 20. The invention as defined in claim 16including pressure responsive means connected with at least one of saidchambers and with said voltage source and adapted to vary the currentflow through the cell in accordance with pressure changes.
 21. Theinvention as defined in claim 16 wherein both of said electrodes arecomposed of a palladium and silver alloy of about 25 percent and about75 percent palladium and wherein said electrolyte is an aqueous solutionof sodium hydroxide at a concentration of approximately 80 weightpercent of sodium hydroxide and wherein said cell is operated at atemperature of about 200*C.
 22. A load device having a hydrostatic gasbearing with supply and exhaust passages, a plurality of electrolyticcells each having anodic and cathodic electrodes with an electrolytetherebetween, each of the electrodes being in the form of a membrane andof a material adapted to transmit hydrogen by diffusion from one of itssurfaces to the other, a low-pressure inlet chamber, each of said cellshaving one side of its anodic electrode communicating with the inletchamber, a high-pressure outlet chamber, each of said cells having oneside of its cathodic electrode communicating with the outlet chamber,the high-pressure outlet chamber being connected with the supply passageof the bearing and the low-pressure inlet chamber being connected withan exhaust passage of the bearing, and voltage supply means connectedwith each of said cells whereby hydrogen gas is circulated through thebearing.
 23. The invention as defined in claim 22 wherein the voltagesupply means includes a voltage source with said cells being connectedin series with each other across the voltage source.
 24. The inventionas defined in claim 22 wherein said plurality of cells includes firstand second groups of cells, said voltage supply means includes a voltagesource with the cells of each group being connected in series with eachother across the voltage source and the first and second groups of cellsbeing connected in parallel across the voltage source.
 25. The inventionas defined in claim 22 wherein said load device comprises a laserscanner in a sealed container and the low-pressure inlet chamber isconnected with the exhaust passage of the bearing through said containerwhereby said container is evacuated to a low pressure thereby reducingthe windage loss arising from high-speed rotation of said scanner.